1. Technical Field
The present invention generally relates to power saving switches, and more particularly to a magnetic power saving switch for a portable electronic apparatus.
2. Description of Related Art
In recent years, portable electronic devices such as mobile phones, personal data assistants (PDA), hand-held computers, and notebook computers have been widely used due to their convenience and practicality. In general, the display component of these portable electronic devices consumes an inordinate amount of energy when the portable electronic devices are operated. The best way to save energy is by powering off the screen while keeping the portable electronic device operated when not in use. This will help extend the life of the screen and decrease electromagnetic radiation from the screen.
One technique of turning off the display when the lid is closed is by a controlling switch. Portable electronic devices include a main body and a lid pivotably connected to one side of the main body. The display is embedded in the lid. The controlling switch includes a magnetic body mounted on the lid and a magnetic detector mounted on the main body. The magnetic detector detects the position of the lid according to a magnetic field intensity of the magnetic body. For example, when the lid rotates from an open position to a closed position, the magnetic detector gradually detects a stronger magnetic field, and outputs a signal to turn off the display when the magnetic field is strong enough, that is when the lid is almost in a closed position.
Magnetic substances, such as metal keys, near or adjacent to the portable electronic device may affect the strength of the magnetic detector. As such the display may not turn off even when the lid is very close to the magnetic detector and the display will consume power even when the lid is closed. Thus, these magnetic substances next to the portable electronic device manually, may cause great inconvenience to the user.
Therefore, a reliable screen controlling switch for controlling the screen to turn on or turn off is needed.